Where do I start?
My thought has always been that running a business is a big commitment - time, money, energy, etc. - so you better do something you love. If it's simply about making money (not that that isn't a part of it), it's easier to get a job and a lot less risky.
Starting a business is about risk and rewards. You risk time and capital; the potential reward is financial success, independence, creative control, setting your own hours, etc.
I think one of the best places to start is the SBA - Small Business Administration - http://www.sba.gov/. They offer a whole slew of Resource Partners - SCORE, Women’s Business Centers & Small Business Development Centers. http://www.sba.gov/services/counseling/index.html.
Another option is that many organizations offer a class to help with writing a business plan. Check with the local SBA Chapter to see if they can refer to you one, if they don't offer it themselves. In going through a guided process of writing a business plan, you should get a sense of what you'll be undertaking and how much money you will need to get it going.
These sources should help you begin to figure out some of your questions.
Godd luck . . .
